Light-sensitive imaging materials containing azole/aldehyde condensates and halogenated hydrocarbons



3,489,568 LIGHT-SENSITIVE IMAGING MATERIALS CON- TAINING AZOLE/ALDEHYDE CONDENSATES AND HALOGENATED HYDROCARBONS Ernst August Hackmann and Johannes Muuder, Wiesbaden-Biebrich, Germany, assignors to Kalle Aktiengesellschaft, Wiesbaden-Biebrich, Germany, a corpora tion of Germany No Drawing. Filed Aug. 19, 1965, Ser. No. 481,117 Claims priority, application Germany, Aug. 22, 1964, K 53,818 Int. Cl. G03c 1/64 US. Cl. 96-90 20 Claims ABSTRACT OF THE DISCLOSURE Light-sensitive, negative-working reproduction materials suitable for use in image copying with ultraviolet light source are prepared by coating a support with a light-sensitive imaging composition comprising a halogenated hydrocarbon, and a condensation product of (a) an aldehyde and (b) androgen-containing, S-membered heterocyclic ring compound. The improved imaging material may be sensitized to incandescent light sources by the addition of a ferrocene.

The present invention relates to light-sensitive layers and refers more particularly to reproduction materials utilizing such novel, highly light-sensitive negative-working layers.

In the prior art, it is known that methyl indoles and phenyl indoles, such as 2,3-dimethyl indole and l-methyl- 2-phenyl-indole, form dyestuffs with halogenated hydrocarbons, such as bromoform, iodoform and the like, when they are exposed to ultraviolet radiation. However, in ad dition to their relatively low light-sensitivity, these reproduction materials have a very unpleasant smell, even after fixation.

Therefore, one object of the present invention is to pro- United States Patent vide light-sensitive materials which overcome the disad- I tion materials having superior light sensitivity to the ma- I terials previously known. v

Other objects will become apparent in the course of the following specification.

In the present invention, condensation products of nitrogen-containing heterocyclic compounds having a quasiaromatic 5-membered ring with aldehydes form dyestuffs when exposed to ultraviolet light. This efiect is considerably increased by the presence of halogenated hydrocarbons.

Furthermore, it has been found that the light-sensitivity of the condensation products of' nitrogen-containing, heterocyclic quasi-aromatic compounds having a S-membered ring and the aldehydes is capable of a particularly significant increase, when not only halogenated hydrocarbons are added, but-also ferrocene or substituted ferrocene. In particular, a sensitivity to light in the visible region of the spectrum is thus obtained, which is satisfactory for practical purposes. Besides ferrocene, aromatic aldehydes such as benzaldehyde, 3,4-methylene-dihydroxy-benzaldehyde, or dimethylaminobenzaldehyde may be added for improving the light sensitivity.

The light-sensitive material of the present invention comprises a support such as paper, metal or plastic film such as polyester film, cellulose ester film or saponified cellulose, and a light-sensitive layer including at least one condensation product of one or more nitrogen-containing, heterocyclic, quasi-aromatic compounds having a 5-membered ring with one or more aldehydes. The compound may be substituted. As a substitute for, orin addition to the condensation product, the layer may also contain at least one condensation product of one or more nitrogencontaining, heterocyclic, quasi-aromatic compounds having a 5-membered ring with one or more aldehydes and at least one amine. In addition to said condensation product, the layer includes at least one halogenated hydrocarbon.

Condensation products of nitrogen-containing, heterocyclic compounds having a quasi-aromatic 5-membered ring with aldehydes according to the present invention are those compounds obtained from two moles of indole or a mixture of different indoles, which may be substituted at the indole nucleus as well as at the aromatic nucleus, and one mole of aldehyde according to the following equation:

The reaction is performed in a known manner in an alcoholic solution, in the presence of acid catalysts such as mineral acids or zinc chloride (see E. Fischer Liebigs Ann. Chem, 242, page 372, 1887). It is possible to start with one substituted indole or with a mixture of substituted indoles to form asymmetrical condensation products as well as symmetrical products.

In the general formula for'the aldehyde component given above, R may be hydrogen, alkyl, aryl, substituted aryl, alkenyl, aralkyl, or a heterocyclic radical. Examples of such compounds are: benzaldehyde; 4-dimethylaminobenzaldehyde, 3,4-dichloro-benzaldehyde; 4-chloro-benzaldehyde; 3-nitrobenzaldehyde; 3,4-methylene-dihydroxybenzaldehyde; 4-hydroxy-benzaldehyde; cinnamic aldehyde; 4-amino-cinnamic aldehyde; indole-3-aldehyde;

phenyl-pro ionaldehyde; formaldehyde, acetaldehyd e and X which may be identical or dilferent and may be hydroxyl, alkoxy, halogen, carboxyl, hydrogen or carboxyalkyl.

Instead of the condensation products of indoles and aldehydes, analogous products of pyrroles, pyrazoles, imidazoles, 1,2-substituted pyrazolones, triazoles, and tetrazoles with the aldehydes may be usedfor the prepara-: tion of the present light-sensitive layers. Mixtures of these compounds may be used forthe preparation of the condensation products.

Pyrroles used according to the present invention in.- clude pyrrole itself and derivatives having up to four substituents with one alpha-position with respect to the 3 nitrogen being left unsubstituted. The pyrroles have the following general formula:

I t l 11 N 14 N I it. 1's,

wherein R R and R may be identical or different and have the meaning given above for R R R and R in connection with the indoles. The condensation products were prepared in accordance with the method described by L. Knorr in Liebigs Annalen der Chemie, 238, page 214 (1887).

The condensation products of triazole or substituted triazoles used according to the present invention are derived from the following general formula:

I Rn In this formula R and R may be identical or different and have the meaning stated above in connection with R R R and R for indole. The condensation products are prepared analogously to the condensation products of the indoles.

The condensation products of tetrazole are derived from tetrazoles of the following general formula:

wherein R has the meaning stated above for R R R and R for the indoles. The tetrazoles may be reacted with aldehydes in the same manner as the indoles.

A further group of condensation products of the above named compounds with a nitrogen containing quasi-aro matic -membered ring is obtained by reacting them with an aldehyde and an amine, preferably a secondary amine, in a kind of Munich-reaction. In the following equation 4 given for such a reaction, the compounds used are indole, salicylic aldehyde, and piperidine;

The reaction was performed in accordance with the method described by M. Scholz in Berichte der Deutschen Chemischen Gesellschaft, 46, 2138 (1913).

Secondary amines are preferred as the amine component in the reaction stated above. Examples are dialkylamines, alkyl aryl amines, and heterocyclic amines, such as dimethyl amine, methyl aniline, piperidine, pyrrolidine, and morpholine.

In the following table, the general formulas are given for a number of typical condensation products:

(1) R71- R3 1? Ri-LTFR R6 N CH I -Rt I! s Pyrroles and aldehyde CH X -Ra Ra X1 \N/ \N/ I'M II Indoles and aldehyde (3) Indole and aldehyde and piperidine R11 CH R11 i Rlfl- O m I R11! R15 Pyrazolones and aldehyde (5) Rn n F R W R14 Rr4 H i R12 R12 Imidazoles and aldehyde R C R Triazoles and aldeh de m rm y N R NN n; L I l Tetrazoles and aldehyde N r N genated hydrocarbons:

R2l\ Rzz-C-Xz In this formula, X stands for chlorine, bromine or iodine, and R R and R may be identical or different and may stand for chlorine, bromine, iodine, hydrogen, alkyl (which may be substituted by chlorine, bromine or iodine), aryl, aralkyl, alkenyl or a heterocyclic group. Furthermore, carboxylic acid chlorides and their derivatives, and halogenated synthetic substances such as chlorinated rubber may be used.

The following compounds are given as examples: pentabromoethane; hexachloroethane; w,w,wtribromoacetophenone; benzotrichloride; cyanuric chloride; iodoform; bromoform; and hexachloro-cyclohexane.

The following compounds are pointed out as particularly advantageous; tetrabromomethane; 4-bIOm0-(w,w,wtribromo) acetophenone; 2,4-dirnethyl-(w,w,w-tribromo)- acetophenone; and 3-nitro- (w,w,w-tl'ib '0m0 -acetophenone.

The light-sensitivity of layers consisting of condensation products of nitrogen-containing heterocyclic quasi-aromatic 5-membered ring compounds with aldehydes and halogenated hydrocarbons may be considerably increased, particularly in the visible range of the spectrum, by adding ferrocene or a substitution product of ferrocene. Suitable substituted ferrocenes are: diacetyl ferrocene, dipropionyl ferrocene, dibenzoyl ferrocene, bis-(3-nitrobenzoyl)-ferrocene, bis-(4-dimethyl-amino-benzoyl) ferrocene, and ferrocene dicarboxylic acid. These compounds may be added either individually or in admixture with each other. Together with the above ferrocenes, aromatic aldehydes such as benzaldehyde, 3,4-methylene-dihydroxy-benzaldehyde, dimethylamino-benzaldehyde, and indole-3-aldehyde may be added.

The reproduction materials prepared in accordance with the invention are highly light-sensitive and practically odorless. The condensation products possess relatively high melting points so that they do not escape from the layer when the material is stored.

For the preparation of a reproduction material according to the present invention, a solution containing one or more of the condensation products and one or more halogenated hydrocarbons is applied to a support and the solvent is evaporated. Ferrocene and/or aldehyde may be added to the solution. Suitable supporting materials are wood, glass, plastic films, metal foils, fabrics, and cellulose derivatives, such as cellulose triacetate and paper. For improving the adhesion of the layers to supports with smooth surfaces and for the preparation of thicker layers, natural or synthetic resins or waxes may be added to the light-senstitive substances. For improving the shelf life of the unexposed reproduction materials, an essential component of the light-sensitive layer (for example, the halogenated hydrocarbon) may be added in the form of a gas shortly before exposure. Suitable light sources for the present process are commercial mixed light and ultraviolet radiators. When ferrocene is added, customary incandescent bulbs are sufficient.

When volatile halogenated hydrocarbons are used, fixation of the exposed materitls is effected by a brief heattreatment at C. to 120 C., (for example, in a drying cupboard, by means of heated plates, or an infrared source, or by passing the materials over a heated roller). Halogenated hydrocarbons which are not volatile under these conditions may be removed by washing with organic solvents, such as ligroin, petrol ether, and the like. The material of the present invention may be used for the preparation of contact copies as well as reflex copies. It is particularly suitable for the production of reenlargements from microfilms.

The present invention is further illustrated by the following examples which are not intended to limit the scope of the present invention.

EXAMPLE 1 An absorbent base paper customarily used for reproduction purposes Was soaked with a solution of 0.2 g. of a condensation product of 2-methyl-indole and 4-dimethylamino-benzaldehyde in 10 m1. of acetone. After evaporation of the solvent, the coated paper was exposed for two minutes to a carbon arc lamp under a master. A negative red copy of the master was produced.

The condensation product was prepared by dissolving two moles of Z-methyl-indole and 1 mole of 4-dimethy1- amino-benzaldehyde in ethanol and adding a small quantity of hydrochloric acid. When the reaction mixture was heated on a water bath, the condensation product precipitated in crystalline form.

EXAMPLE 2 An absorbent base paper customarily used for reproduction purposes was soaked with a solution of 0.2 g. of the condensation product of Z-methyl-indole and 4-dimethylamino-benzaldehyde and 1.0 g. of tetrabromomethane in 10 ml. of acetone. After evaporation of the solvent, the material was exposed for five seconds to a carbon arc lamp under a master. The exposed paper was fixed by heating for two minutes at C. in a drying cupboard. A negative red copy of the master was obtained.

EXAMPLE 3 An absorbent base paper customarily used in the reproduction field was soaked in a solution of 0.2 g. of the condensation product of Z-methyl-indole and 4-dimethyl amino-benzaldehyde, 1.0 g. of tetrabromomethane, and 0.3 g. of ferrocene in 10 ml. of acetone. After evapo ation of the solvent, the material was exposed for ten seconds to a ZOO-watt incandescent bulb under a master. The exposed paper was then fixed by heating it for two minutes to 100 C. in a drying cupboard. A negative red copy of the master was obtained.

EXAMPLE 4 An absorbent base paper customarily used in the reproduction field was soaked in a solution of 0.2 g. of the condensation product of Z-methyl-indole and cinnamic aldehyde, 1.0 g. of tetrabromomethane, and 0.3 g. of ferrocene in 10 ml. of acetone. After evaporation of the solvent, the material was exposed for ten seconds to a ZOO-watt incandescent bulb under a master. The exposed paper was heated for two minutes to 100 C. in a drying cupboard as in Example 3. A negative green copy of the master was obtained. The condensation product was prepared as described in Example 1.

EXAMPLE 5 An acetate film was coated with a solution of 0.1 g. of the condensation product of 2-methyl-indole, benzaldehyde piperidine, 1 g. of tetrabromomethane, 0.3 g. of ferrocene, and 0.5 g. of polystyrene in 10 ml. of a solvent mixture consisting of equal parts of acetone and trichloroethylene by volume. After evaporation of the solvent, the material was exposed for one second to a carbon arc lamp under a master. The exposed film was fixed by passing it under an infrared radiator. A red copy of the master was obtained which could be used for making futher reproductions on photoprinting paper.

The condensation product was prepared by dissolving one mole of 2-methyl-indole, 0.96 mole of benzaldehyde and 0.59 mole of piperidine in three times their own quantity of ethanol, allowing the mixture to stand overnight, and then adding water until it became turbid, whereupon the condensation product precipitated in crystalline form.

EXAMPLE 6 -An absorbent base paper as customarily used in the reproduction field was soaked with a solution of 0.2 g. of the condensation product .of 1-phenyl-2,3-dimethylpyrazolone-(S) and benzaldehyde, 0.3 g. of ferrocerie, and 1.0 g. of tetrabromomethane in ml. of a solvent mixture consisting of equal parts by volume of acetone and trichloroethylene. By means of a 500-watt projector lamp, an 8 enlargement was produced on this paper from a silver halide negative film. The exposure time was 45 seconds. After fixation in a drying cupboard, a distinct yellow-brown image was obtained on a colorless background.

The condensation product was prepared by dissolving 1-phenyl-2,3-dimethyl-pyrazolone in benzaldehyde and adding a small quantity of concentrated hydrochloric acid. The condensation product precipitated in the form of the hydrochloride, from which it was recovered by means of sodium hydroxide solution.

EXAMPLE 7 An absorbent base paper was soaked in a solution of 0.2 g. of the condensation product of 2-methyl-4-phenyl- 3-acetyl-pyrrole and benzaldehyde, 0.3 g. of ferrocene, and 1.0 g. of tetrabromomethane in 10 ml. of a mixture consisting of equal parts by volume of acetone and trichloroethylene, and the solvent was evaporated. In the manner described in Example 6, a re-enlargement was produced from a silver halide negative film. A rust-brown copy was obtained on a colorless background. The condensation product was prepared as described in Example 1.

EXAMPLE 8 A baryta paper was coated with a solution of 0.1 g. of the condensation product of l-methyl-Z-phenyl-indole and cinnamic aldehyde, 0.2 g. of 3,4-methylene-dihydroxybenzaldehyde, 0.3 g. of ferrocene, and 1.5 g. of tetrabromomethane in 10 ml. of acetone and then dried. On the reproduction material prepared in this manner, an enlargement at a scale of 1:10 was produced from a silver halide negative film by means of a 500-watt projector lamp. The exposure time was ten seconds. After exposure, the material was fixed in a drying cupboard at a temperature of 100: C. A green, easily legible image was obtained on a colorless background. The condensation product was prepared as described in Example 1.

EXAMPLE 9 EXAMPLE 1() A baryta paper was coated with a solution of 0.1 gram of the condensation product of 1-phenyl-2,3-dimethylpyrazolone-(5) and benzaldehyde, 0.2 gram of 3,4- methylene-dihydroxy-benzaldehyde, 0.3 gram of ferrocene, and 1.5 gram of tetrabromomethane in 10 ml. of

acetone and then dried. Whenv a -re-enlargement was produced from a silver halide negative film as described in Example 8, a reddish-brown -.image was obtained on a colorless background. The condensationflproduct Was prepared by the method described in Example 6.

It is apparent that the described examples are capable of many variations and modifications. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A light-sensitive reproduction material comprising ,(a) a support; and v (b) a light-sensitive layer coated on said support, said layer comprising i (1) a halogenated hydrocarbon, and

(2) a condensation product of an aldehyde with at least one nitrogen-containing heterocyclic compound selected from the group consisting of indoles, pyrroles, pyra zoles, imidazoles, pyrazolones, triazoles, and tetrazoles. i

2. A material in accordance with claim 1 in which said condensation product includes a secondary amine.

3. A material in accordance with claim 1 in which said layer includes a ferrocene.

4. A material in accordance with claim 1 in which said layer includes anaromatic aldehyde.

5. A material in accordance with claim 1 in which said layer includes a ferrocene and an aromatic aldehyde. 7

6. A material in acordance with claim 1 in which said compound is an indole of the general formula:

wherein R and R are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, aralkyl, and aryl; X is selected from the group consisting of hydrogen, hydroxy, alkoxy, halogen, carboxyl and carboxyalkyl; and n is from one to four; and said aldehyde has the general formula:

where R is selected from the group consisting of hydrogen, alkyl, aryl, substituted aryl alkenyl, aralkyl and heterocyclic ring.

7. A material in accordance with claim 1 in which said compound is a pyrrole having the general formula:

where R R R and R are each members independently selected from the group consisting of hydrogen, alkyl, alkenyl, acyl, aralkyl, alkaryl and aryl.

8. A material in accordance with claim 1 in which'said compound is a pyrazole having the general formula:

where "R R and R are each members independently selected from the group consistingofhydrogen, alkyl, alkenyl, aralkyl, alkaryl, and aryl. v

9. A material in accordance with claim 1 in which said compound is an imidazole having the general formula:

where R and R are each members independently selected from the group consisting of hydrogen, alkyl, alkenyl, aralkyl, alkaryl and aryl.

12. A material in accordance with claim 1 in which said compound is a tetrazole of the following general formula:

where R is a member selected from the group consisting of hydrogen, alkyl, alkenyl, aralkyl, alkaryl and aryl. 13. A material in accordance with claim 1 in which said halogenated hydrocarbon has the general formula:

where X is a member selected from the group consisting of chlorine, bromine, and iodine, and where R R and R are each independently selected members from the group consisting of chlorine, bromine, iodine, hydrogen, halogen-substituted alkyl, aryl, aralkyl, alkyl, alkenyl and heterocyclic ring.

14. A material in accordance with claim 1 in which said halogenated hydrocarbon is selected from the group consisting of: tetrabromomethane, 4-bromo-omega, omega, omega-tribromo)-acetophenone; 2,4-dimethyl-(omega, omega, omega-tribromo)-acetophenone; and 3-nitro- (omega, omega, omega-tribromo)-acetophenone.

15. A material in accordance with claim 1 in which said layer contains at least one compound selected from the group consisting of ferrocene, diacetyl-ferrocene, dipropionyl-ferrocene, dibenzoyl-ferrocene, bis(3 nitrobenzoyl)-ferrocene, bis-(4-dimethylamino benzoyl) ferrocene, and ferrocene dicarboxylic acid.

16. A material in accordance with claim 1 in which said layer comprises the condensation product of Z-methyl-indole and 4-dirnethylamino-benzaldehyde and tetrabromomethane.

17. A material in accordance with claim 1 in which said layer comprises the condensation product of Z-methyl-indole and cinnamic aldehyde, tetrabromomethane, and ferrocene.

18. A material in accordance with claim 1 in which said layer comprises the condensation product of 2-methyl-indole, benzaldehyde, and piperidine; tetrabromomethane; ferrocene; and polystyrene.

19. A material in accordance with claim 1 in which said layer comprises the condensation product of l-phenyl-2,3-dimethyl-pyrazolone-(5) and benzaldehyde; ferrocene; and tetrabromomethane.

20. A material in accordance with claim 1 in which said layer comprises the condensation product of l-methyl-Z-phenyl-indole and cinnamic aldehyde; 3,4-methylenedihydroxy-benzaldehyde; ferrocene; and tetrabromomethane.

References Cited UNITED STATES PATENTS 3,335,008 8/1967 Dubose 96-49 3,164,467 l/1965 Sprague et a1. 9648 3,056,673 10/1962 Wainer 9648 NORMAN G. TORCHIN, Primary Examiner M. F. KELLEY, Assistant Examiner US. Cl. X.R. 9692 

